Floor Function

AtCoder

IDabc165_d

Time2000ms

Memory256MB

Difficulty—

Given are integers $A$, $B$, and $N$. Find the maximum possible value of $floor(Ax/B) - A × floor(x/B)$ for a non-negative integer $x$ not greater than $N$. Here $floor(t)$ denotes the greatest integer not greater than the real number $t$. ## Constraints * $1 ≤ A ≤ 10^{6}$ * $1 ≤ B ≤ 10^{12}$ * $1 ≤ N ≤ 10^{12}$ * All values in input are integers. ## Input Input is given from Standard Input in the following format: $A$ $B$ $N$ [samples]

Samples

Input #1

5 7 4

Output #1

2

When $x=3$, $floor(Ax/B)-A×floor(x/B) = floor(15/7) - 5×floor(3/7) = 2$. This is the maximum value possible.

Input #2

11 10 9

Output #2

API Response (JSON)

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      "content": "Given are integers $A$, $B$, and $N$. Find the maximum possible value of $floor(Ax/B) - A × floor(x/B)$ for a non-negative integer $x$ not greater than $N$. Here $floor(t)$ denotes the greatest intege",
      "description_type": "Markdown"
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      "memory_limit": 262144
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    "difficulty": "None",
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  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Given are integers $A$, $B$, and $N$.\nFind the maximum possible value of $floor(Ax/B) - A × floor(x/B)$ for a non-negative integer $x$ not greater than $N$.\nHere $floor(t)$ denotes the greatest intege...",
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